decreased 5 times
Explanation: if the force increases 5 times between them would decrease 5 times
It’s E we just had a test in this and I got it right
Answer:
the power that must be supplied to the motor is 101.45 hp
Explanation:
Given that,
The weight of elevator = 1000lb
The motor exerts a constant force of 500 lb on the cable
The load has been hoisted s = 15 ft starting from rest
The motor has an efficiency of e = 0.65
According to the equation of motion:
F = ma


To calculate the output power:
P(out) = F. v
P(out) = 3 (500) * 21.98
P(out) = 32970 lb.ft/s
As efficiency is given and output power is known, we can calculate the input power.
ε = P(out) / P(in)
0.65 = 32970 / P(in
)
P(in) = 50,723 lb.ft/s
P(in) = 50,723 / 500 hp
= 101.45 hp
the power that must be supplied to the motor is 101.45 hp